//Author: Fuadul Hasan(fuadul202@gmail.com)
//BSMRSTU,Gopalganj
//#include<bits/stdc++.h>
#define _USE_MATH_DEFINES
#include <set>
#include <map>
#include <list>
#include <queue>
#include <stack>
#include <cmath>
#include <ctime>
#include <cstdio>
#include <string>
#include <vector>
#include <bitset>
#include <random>
#include <cassert>
#include <cstring>
#include <sstream>
#include <complex>
#include <numeric>
#include <iostream>
#include <algorithm>
#include <functional>
#include <unordered_set>
#include <unordered_map>
using namespace std;

//int input........
template <typename T> inline void readline(T &n) {n = 0; int f = 1; register int ch = getchar();
 for (; !isdigit(ch); ch = getchar()) if (ch == '-') f = -1;for (; isdigit(ch); ch = getchar()) n = (n << 3) + (n << 1) + ch - '0';n = n * f;}
 template <typename T, typename TT> inline void readline(T &n, TT &m) { readline(n); readline(m); }
template <typename T, typename TT, typename TTT> inline void readline(T &n, TT &m, TTT &l) { readline(n, m); readline(l);}
// long long input........
template <typename T> inline void readlinel(T &n) {n = 0; long long f = 1; register long long ch = getchar();
 for (; !isdigit(ch); ch = getchar()) if (ch == '-') f = -1;for (; isdigit(ch); ch = getchar()) n = (n << 3) + (n << 1) + ch - '0';n = n * f;}
template <typename T, typename TT> inline void readlinel(T &n, TT &m) { readlinel(n); readlinel(m); }
template <typename T, typename TT, typename TTT> inline void readlinel(T &n, TT &m, TTT &l) { readlinel(n, m); readlinel(l);}
//debug..........
#define error(args...) {vector<string>_v=split(#args,',');err(_v.begin(),args);cout<<endl;}
vector<string> split(const string &s, char c) {vector<string>v; stringstream ss(s); string x;while (getline(ss, x, c))v.emplace_back(x); return move(v);} void err(vector<string>::iterator it) {}
template<typename T, typename... Args>void err(vector<string>::iterator it, T a, Args...args) {cout << it->substr((*it)[0] == ' ', it->length()) << " = " << a << " "; err(++it, args...);}

//............ignore it..................//
#define F first
#define S second

#define Pi atan(1)*4
#define mp make_pair
#define pb  push_back
const int M    = 1e9 + 7;

#define ll  long long int
#define happy cin.tie(0);

#define point(x) setprecision(x)
void Print(int n){printf("%d ", n);}
void print(int n){printf("%d\n", n);}
#define Test printf("Case %d: ",tc++);
int length(string s){return s.size();}
void print(ll n){printf("%I64d\n", n);}
void Print(ll n){printf("%I64d ", n);}

#define coding ios::sync_with_stdio(false);
#define Unique(c) (c).resize(unique(all(c))-(c).begin())
void print(int n,int m){printf("%d ",n);printf("%d ",m);}
void print(ll n,ll m){printf("%I64d ",n);printf("%I64d ",m);}
#define vout(v) for (auto z: v) cout << z << " "; cout << endl;

int length(long long x){int l = 0;for(long long i=x;i;i/=10)l++;return l;}
int dx[8]= {1,0,-1,0,-1,-1,1,1};int dy[8]= {0,1,0,-1,-1,1,-1,1}; int tc = 1;
void print(int n,int m,int k){printf("%d ",n);printf("%d ",m);printf("%d ",k);}
void print(ll n,ll m,ll k){printf("%I64d ",n);printf("%I64d ",m);printf("%I64d ",k);}
long long power(long long a,long long n){ll res = 1;while(n){if(n&1) res = ((res%M)*(a%M))%M;a = ((a%M)*(a%M))%M;n>>=1;}return res%M;}

inline void read(std::vector<int> &v){for(int i=0;i<(int)v.size();i++){readline(v[i]);}}
inline void read(std::vector<ll> &v){for(int i=0;i<(int)v.size();i++){readlinel(v[i]);}}
template<class T> bool remin(T& a, const T& b) { return a > b ? a = b, 1 : 0; }
template<class T> bool remax(T& a, const T& b) { return a < b ? a = b, 1 : 0; }
inline void read(int v[],int n){for(int i=0;i<n;i++){readline(v[i]);}}
inline void read(ll v[],int n){for(int i=0;i<n;i++){readlinel(v[i]);}}

inline int add(int a, int b, int mod) {a += b ; return a >= mod ? a - mod : a ;}
inline int sub(int a, int b, int mod) {a -= b ; return a < 0 ? a + mod : a ;}
inline int mul(int a, int b, int mod) {return (ll)a * b % mod ;}

#define   pr     pair<int, int> 
#define   vpr     vector<pr> 
#define   vi       std::vector<int>
#define   vll      std::vector<ll>
#define   all(n) n.begin(),n.end()


const int Inf           = (int)2e9 + 5;
const ll  Lnf           = (ll)2e18 + 5;
const int N             = 5e5 + 5;
const int NN            = 1e6 + 5;



int solve() 
{
    //happy coding

    
    string s;
    cin>>s;

    int x = s.size();

    cout<<(x+1)/2<<endl;


    return 0;
    //error();
}
int main(){
    int test = 1;
    //readline(test);//(void)getchar();
    while (test--)solve();return 0;
}